What condition may result in the evaporation coil freezing?

The freezing of the evaporation coil is typically a result of conditions that disrupt the normal flow of refrigerant or reduce the heat transfer capability in the coil. When there is a blockage in the refrigerant lines, it can prevent the refrigerant from circulating properly through the evaporator coil. This stagnation leads to reduced pressure and temperature, causing moisture in the air around the coil to freeze.

Additionally, a low refrigerant charge can also lead to this condition. Insufficient refrigerant means that there is not enough fluid to absorb the heat from the air. As a result, the evaporator coil may not maintain its intended operational temperatures, leading to freezing as the heat transfer is impaired.

High ambient temperature does not typically lead to the freezing of the coil, as warmer conditions usually promote proper refrigerant flow and heat exchange. Thus, both a blockage in the refrigerant lines and a low refrigerant charge are correct conditions that can result in the evaporation coil freezing, making the combined answer the most accurate.